1. Field of the Invention
The present invention relates to a motion detection device for use in compressing a moving picture, an MOS integrated circuit including such a motion detection device, and a video system using such a motion detection device.
2. Description of the Background Art
There are signal processing techniques at present capable of compressing images with high compression rates, and they have been used in digital still cameras, digital video cameras, etc.
A commonly-known method for compressing a moving picture is the MPEG (Moving Picture Experts Group) method. The MPEG method employs motion compensation, with which images can be compressed efficiently by encoding the displacement of an object and the image difference data. The motion compensation technique calculates a motion vector representing the displacement of an object by using a calculation method such as a block matching method.
For example, Japanese Laid-Open Patent Publication No. 2005-210647 discloses a detection device and a detection method for detecting a motion vector. Where the detection device disclosed in Japanese Laid-Open Patent Publication No. 2005-210647 detects a motion vector for a second current macroblock image adjacent to a first current macroblock image after detecting a motion vector for the first current macroblock image, it is possible to suppress a reference macroblock image from being transferred redundantly from a reference frame memory to a reference image data buffer.